Suspicious of blue white veil
This lesion on the trunk of an older white patient was referred by a GP who had viewed it dermoscopically and wondered about a blue white veil. This is a very worrying feature when seen in a melanocytic lesion.
It s never wrong to seek advice about a suspicious pigmented lesion. The dermoscope was applied in clinic revealing the following.
The most basic algorithm that can be applied to lesions can be described as the two step algorithm and it was taught to me in the first lecture on dermoscopy I ever attended about 13 years ago, by a plastic surgeon whose name (as far as I recall) was Marc Moncrieff.
step 1)-is this lesion melanocytic?
step 2) if yes, could it be a melanoma?
this lesion is not melanocytic. Why? because it has global features which are typical of a haemangioma, namely lacunae of blood. These structures may be red, blue or mauve/purple, which depends on the state of oxygenation of the blood. They may be black if thrombosed. Also there must be no features of any other type of lesion. Haemangiomas may not, for example, have reticular pigment network or brown globules which would point to a melanocytic lesion.
Having established on positive grounds (features present) and also negative grounds (features that are absent) that this lesion is not melanocytic, we don’t have to worry about it being a melanoma, i.e. step 2 does not arise.
I find that learners often see a misty out of focus blue/white colouration in benign lesions and worry about melanoma. The presence of blue white/blue grey veil in an undoubted melanocytic lesion is very sensitive for melanoma, but we can see similar colours in some non melanocytic lesions, particularly haemangiomas and seborrhoiec keratoses. Some of the colour in this lesion is out of focus, but there are some red lacunae in focus and these are extremely typical. The laws of optics only allow us to focus on part of the lesion, so part will be out of focus where the lesion is not flat.
Do not worry, this all becomes clearer through examining hundreds of cases. Google Images is a very good source of lesions, search on dermoscopy + search term (i.e. blue white veil or haemangioma).